FRENCH POP booms are a bit like US presidential scandals: every decade's got to have at least one. However, judging by the sustained interest in various Gallic bands over the past couple of years, the latest nouvelle vague may actually have washed up something of enduring value. At the forefront of this is Air, whose full name, French Band, suggests that they are aware of the national reputation for pop abominable.

"Sexy Boy" and "Kelly Watch the Stars", the two hit singles from their impressive debut album Moon Safari, typified Air's distinctive approach: repeated, breathless vocals, reminiscent of Serge Gainsbourg, floating on funk and electro-pop compositions. But whereas their compatriots, notably Daft Punk and Motorbass, specialise in dance, Jean Benoit Dunckel and Nicolas Godin's gorgeous arrangements of vintage keyboards and the occasional vocals of American folk singer Beth Hirsch coalesce into something approaching traditional songs. It was labelled lounge music, but Moon Safari's air of sincerity, not to say earnestness, is anything but kitsch.

Unsurprisingly, Air had wondered how they were going to maintain this other-worldliness when they toured the album. The choice of the Theatre Royal, Drury Lane, for the first of two London gigs was a daring step in the right direction.

Godin and Dunckel had charm on their side. They and their backing group bounded on stage all in white, grinning at their good fortune, waving at their friends in a box to the right and chatting to the audience through a vocoder.

Wisely, though, they kept Moon Safari's astral whimsy to a minimum. To open their set, there was a quick burst of the five-note sequence from Close Encounters of the Third Kind but, for the most part, Dunckel and Godin were intent on beefing up their album's air of detached melancholy.

At times, it proved tricky. The weightlessness of digital recording suits Air and their music occasionally sank under the gravity of live performance. However seductive they are on disc, meditative, Kraftwerk-like grooves such as "Le Soleil Est Pres De Moi" or "Remember" sounded like high-class muzak live. On the other hand, "Sexy Boy" and "Kelly Watch the Stars" were compelling. The first had been transformed into irresistible 21st- century funk, while the second blossomed into delightful mid-Eighties electro.

There was substance, then, to the charm but you still felt the Gallic enigma needed some human drama. Cue Beth Hirsch, whose contributions to Moon Safari had provided an already fine album with further highlights. Beyond Air's boundless innovation, here was the warmth the evening had demanded. Her brittle voice insinuated itself amongst the boys' moogs and wurlitzers, igniting the torch songs "All I Need" and "You Make It Easy". It was here, finally, that Air's stratospheric talents really went into orbit.